David e



(No Model.)

D. R. B. 'KENYON. V Polishing and Grinding Machine. No. 239,389.Patented March 29,1881.

- Fl [3- a. WITNE SEEEI- INVENTURI NJ5ETERS. PHOTO-LITMOGRAPHERWASHINGTON. D C.

UNITED STATES PATENT OFFICE.

. DAVID E. B. KENYoN, or PROVIDENCE, nHonE ISLAND.

POLISHING AND GRINDING MACHINE.

SPECIFICATION formingpart of Letters Patent No. 239,389, dated March 29,1881.

Application filed January 17, 1881; (No model.)

To all whom it may concern:

Be it known that I, DAVID R. B. KENYoN, of the city and county ofProvidence, in the State of Rhode Island, have invented certain new anduseful Improvements in Polishing and Grinding Machines, of which thefollowing is a specification.

The object of my invention is to produce a machine susceptible ofadjustment, whereby different degrees of belt-tension may be obtained;and it consists of a stationary frame or standard, an adjustable bearinghaving its boxes provided with anti-friction washers, in which revolvesan ordinary spindle; also, device for vertically adjusting said bearing.

In the accompanying drawings, in which similar letters of referenceindicate like parts, Figure 1 represents an end elevation of themachine, showingthe adjusting device. Fig. 2 is a front view, with upperportion of the boxes in section, showing the anti-friction washers inposition. Fig. 3 is a top view, partly in section, showing thespring-catch for locking the adjustment.

The standard A, which is secured by bolts or otherwise to the bench, hasvertical grooves a, a planed therein to receive the U-shaped casting D.The grooves in the former and the edges of the latter are so formed asto admit of vertical motion only to said piece D. To the standard isattached the ratchet G, which, in connection with the spring-catch K,

prevents the hearing from yielding to the" pressure of the belt. To thestandard is pivoted atoothed lever, H, havingloosely attached theretothe spring-catch K. (Shown in Fig. 3.) The U shaped casting D has itsvertical edges planed to correspond with the grooves a. BoxesE E arecast upon the upper portion of the piece D, and are counterbored toreceive the rawhide and bronze washers e c, said Washers being held inposition and compressed by means of the threaded followers 0 Oil isadmitted through proper openings in the top of the boxes. The rack I issecured to the casting D at a proper position to engage with the toothedlever H. The spindle S is suitably formed to receive the various kindsand sizes of polishing-brushes, bufi's, emery-wheels, &c., used inpolishing, grinding, &c.

The operation of my device is as follows: Assumingthe spindle to berevolving, and desiring to decrease the tension of the belt, thespring-catch K is released from the ratchet U by depressing the smalllever is, and the handle J of the toothed lever H moved upward. Thismotion, by means of the rack I, depresses the U-shaped piece I), andwith it the spindle, 8170., thereby decreasing the distance between thespindle and driviug-shaft and diminishing the tension of the belt, thusadmitting of the spindle being held by the hand while the brushes orbuff, &c., can be changed. By depressing the handle of the lever H anydegree of tension may be maintained, and variations of temperature andstretch of the belt are thereby compensated.

Having thus described my invention, I claim as new and, desire, tosecure by Letters Patent- In a polishing or grinding machine, thecombination, with the frame or standard A, having vertical grooves c a,of the sliding spindlebearing support D and adjusting means H I,substantially as and for the purpose specified.

